The present invention relates to a pushbutton assembly, and more particularly to a pushbutton assembly having a positioning rod rotatably connected to a button and a positioning disk pivotally received in a housing of the pushbutton assembly and having a positioning hole defined in the positioning disk to receive therein a bent of the positioning rod such that repeated up and down movement of the button allows the bent to be positioned at a first position and a second position within the positioning hole to accomplish the designed purpose of the pushbutton assembly.
With reference to FIGS. 1 to 3, a conventional pushbutton assembly is applied in a ball point pen. The ball point pen has a barrel 403, a button 406, a cap 404, a first sleeve 407 and a second sleeve 409. The barrel 403 is provided with a spring 402 and a core 401 received in the barrel 403. The cap 404 has positioning slots 405 defined in an inner periphery of the cap 404 and bars 4051 each alternately formed between, two adjacent positioning slots 405. Each bar 4051 has an inclined top face.
The first sleeve 407 has first bosses 408 formed around an outer periphery of the first sleeve 407 to correspond to the positioning slots 405 of the cap 404. The second sleeve 409 has second bosses 410 formed on an outer periphery of the second sleeve 409 to correspond to the positioning slots 405 of the cap 404. After the cap 404 is assembled with the barrel 403, the button 406 and the first sleeve 407 are slidable relative to the barrel 404. After the assembly of the pen, the user pushes the button 406, the downward movement of the first sleeve 407 drives the second sleeve 409 to rotate, allowing the second bosses 410 to about the top face of the bar 4051 to extend the core 401 out of the barrel, as shown in FIG. 2. However, when the user pushes the button 406 again, the second bosses 410 are thus received in the corresponding positioning slots 405, allowing the core 401 to be retracted in the barrel 403, as shown in FIG. 3. In this type of pushbutton assembly, parts are loosely connected to one another. Thus, every movement of the button 406 creates a lot of friction between parts and that wears out the engaged faces of the parts. From the foregoing description, it is noted that this type of conventional pushbutton assembly not suitable for sophisticated electronic components.
U.S. Pat. No. 4,167,720; U.S. Pat. No. 4,937,548; U.S. Pat. No. 5,223,813 U.S. Pat. No. 5,451,729; U.S. Pat. No. 5,558,211 are numerous patents related to a pushbutton assembly, which all suffer from the following shortcomings:
1. Too many linking parts are involved in a single movement, causing a complex process to accomplish a single purpose and a non-real-time action; and
2. Because the quantity of the parts to accomplish a single action is large, possibility of malfunction is great and the quality of coupling between parts is low.
With reference to FIG. 4, a second conventional pushbutton assembly is shown to have a button 501 and a housing 506.
The button 501 is mounted on top of a body (not numbered) having a V-shaped protrusion 503 which is formed on a bottom of a channel 502 and has a lowermost point (a). The channel 502 has a lowermost point (b). A positioning rod 504 has a first end inserted into the through hole 507 in the housing 506 and a second end 505 extending into the channel 502. A spring 508 is employed to provide a resilience to the button 501 and to ensure that the second end of the positioning rod 502 to abut an inner face of the channel 502.
When the user presses the button 501, the second end of the positioning rod 504 moves from point (a) to point (b). When the user pushes the button 501 again, the second end of the positioning rod 504 moves from point (b) to point (a). After the pushbutton assembly is used for a period of time, the resilience of the spring 508 is deteriorated, and the engagement of the second end 505 of the positioning rod 504 with the inner face of the channel 502 is not secured. Therefore, it is noted that the second end 505 of the positioning rod 504 may deviate from point (a) if the resilience form the spring 508 is not enough. Another shortcoming from the insufficient resilience is that the contact 510 of the electrical plate 509 may not engage with the contact 512 of the pin 511 properly and thus causes malfunction.
Accordingly, the conventional pushbutton assembly uses too many parts so that the cost is high and the possibility of having malfunction is thus high.
To overcome the shortcomings, the present invention tends to provide an improved pushbutton assembly to solve the aforementioned problems.
The primary objective of the present invention is to provide an improved pushbutton assembly having a positioning rod rotatably connected to a button and a positioning disk pivotally received in a housing of the pushbutton assembly and having a positioning hole defined in the positioning disk to receive therein a bent of the positioning rod such that repeated up and down movement of the button allows the bent to be positioned at a first position and a second position within the positioning hole to accomplish the designed purpose of the pushbutton assembly.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.